Re: [Bridge] [Bonding-devel] received packet with own address as source address

[Matthew Kent <matt@bravenet.com>]

On Wed, 2008-12-03 at 16:46 -0800, Jay Vosburgh wrote:
> Matthew Kent <matt@bravenet.com> wrote:
> 
> >Trying to determine if I have a misconfiguration, misunderstanding or
> >have stumbled on a bug.
> >
> >Have a CentOS 5.2 server with 2 e1000e nics in a balance-xor bond, check
> >this out: 
> 
> 	I suspect your switch is misconfigured.
> 	
> 	The balance-xor mode is nominally "Etherchannel compatible" and
> the switch ports connected to bonding balance-xor should be in
> Etherchannel mode ("Trunking", etc, but not "LACP" or "802.3ad").
> 
> 	If the switch doesn't know the ports are aggregated, it may very
> well send broadcasts recieved on one port back out the other port, which
> may be the cause of what you're seeing.  The switch might also whine
> about flapping of the MAC address.
> 
> 	If I set up bonding here with the switch unconfigured for
> Etherchannel, I see the same behavior as this:
> 
> ARPING 172.16.0.117 from 172.16.0.116 eth0
> Unicast reply from 172.16.0.117 [00:15:17:70:A3:88]  0.607ms
> Unicast reply from 172.16.0.117 [00:15:17:70:A3:88]  0.648ms
> Sent 1 probes (1 broadcast(s))
> Received 2 response(s)
> 
> 	Specifically the "Received 2 response(s)" part.  This happens
> because the bond receives one copy of the packet on each port, and
> responds to each.
> 
> 	After I configure the switch ports correctly for Etherchannel,
> there is only 1 response.  Without the switch configuration IPv6
> addrconf also complains about duplicate address detected.
> 
> 	-J

Ah of course! :) Thanks for the helpful information. I should have read
the later section on balance-xor in bonding.txt more closely.
-- 
Matthew Kent \ SA \ bravenet.com